Ultracold Rydberg atoms

Jesús Pérez‐Ríos

H. R. Sadeghpour

S. L. Rolston

Jia Suo-Tang

The dipole blockade of ultracold Rydberg atoms plays a significant role in the formation of quantum logic gate and the investigation of quantum information storage.The interaction between ultracold Rydberg atoms is presented,furthermore the mechanisms of long range Van de Waals interactions and dipole-dipole interactions as well as excitation blockade of ultracold Rydberg atoms are presented.The possibility of constructing quantum logic gate based on single Rydberg atom excitation is described.

Gambhir Ranjit

There is considerable interest in the dynamics of ultracold plasmas and ultracold Rydberg gases. Ultracold plasmas are typically formed by photo-excitation of ultracold atoms to an energy region near (both above and below) an ionization threshold. Excitation to bound, highly-excited Rydberg states can lead to formation of a plasma via several processes, including collisions between Rydberg atoms. Three-body recombination in an ultracold plasma can also result in the production of ultracold Rydberg atoms. Understanding the dynamics of ultracold Rydberg gases is therefore important for understanding the dynamics of ultracold plasmas. In this dissertation, we have investigated the formation and survival of a particular class of Rydberg atoms. These atoms are known as ZEKE state Rydberg atoms, where the term ZEKE is derived from "Zero Kinetic Energy." ZEKE Rydberg states are high angular momentum and high angular momentum projection excited states which can be formed by laser excitation in the presence of electric fields. Without the electric fields, these states would be optically dark. We have investigated ZEKE Rydberg states in ultracold argon in an energy region just below the second ionization threshold of the atoms in our magneto-optical trap. Here, low angular momentum states decay very quickly (< 1 ns) by auto-ionization through a core spin flip due to the Rydberg electron-core interaction. This interaction has been significantly reduced due to the dilution of low l and m states as a result of l and m mixing during excitation. Hence, ZEKE Rydberg states live orders of magnitude longer than low angular momentum states. We are reporting on our experimental investigation of these states in the ultracold regime and prospects for future studies in which external control of these states may be used to control ultracold plasma dynamics.

M. Reetz‐Lamour, Thomas Amthor, Johannes Deiglmayr +2 more